So I've seen in multiple locations that haste > mastery and I get it.

But (maybe I've played too many casters) I can't find anyone mentioning a haste cap. It seems there would be a DR on haste beyond a certain point, where mastery would once again be more important. Does anyone know what that cap is, or of a reliable source where I could read up on it?
Edited by Dedmeat on 12/6/2012 7:30 AM PST